The Billings ovulation metho (BOM) is a method which women use to monitor their fertility, by identifying when they are fertile and when they are infertile during each menstrual cycle. Users pay attention to the sensation at their vulva, and the appearance of any vaginal discharge. This information can be used to achieve or avoid pregnancy during regular or irregular cycles, breastfeeding, and peri-menopause. Described by the BOM organization as "Natural Fertility Regulation", this method may be used as a form of fertility awareness or natural family planning, as well as a way to monitor gynecological health.